I don't think I'm supposed to link to reddit. But, after this latest update (1511) I discovered some strange things happening with sleep and my device was running much hotter than ever before. I always attributed these issues to "someone must be running an app, or doing something wierd, or not updating, etc.". I had not had any issues and I'm rather picky with my software and OCD with keeping clean, optimized devices.
I found a very helpful post there tonight. It pointed me to this link on MS site:
Occasional Black Screen.
While that link is related to the Surface Book, I followed those instructions and it corrected a corrupt file that could not be repaired by the sfc /scannow. Frankly, I didn't even know I had a corrupt file.
After following the instructions, downloading the ISO and right clicking on it to mount the file (don't run the setup.exe) I simply typed from a command prompt DISM /Online /Cleanup-Image /RestoreHealth /source:WIM
:\Sources\Install.wim:1 /LimitAccess (where D is the drive that I mounted) and let it run.
When it was complete, I reran the sfc /scannow and the issue with sleep and excessive heat is gone.
MS has stated that this issue was created with the latest firmware release and many are experiencing these issues. They will likely fix it in a new release but this will mitigate the problems if you run your sfc /scannow and it cannot repair them from an admin prompt, receiving the error 0x800f081f from the results.
I did not use MS Support online. I just did it myself. Took about 45 minutes (including the download) start to finish. Very happy with the results.
I have a SP4 256 with 8 GB RAM and this resolved my issue.